Incidence of tuberculosis in Korean diabetics: Comparison with that in non-diabetic hypertensive subjects

Park, Eun Kyoung; Bae, June Ho; Jung, Yu Min; Chung, Sook Hee; Lee, Jae Hyung; Kim, Sang Hoon; Lee, Byoung Hoon

Abstract

BACKGROUND/AIMS
Tuberculosis remains a major cause of mortality in South Korea, and the prevalence of diabetes is also increasing rapidly. Diabetes is a well known risk factor for tuberculosis. However, the risk varies according to race and regional prevalence. We assessed the potential impact of diabetes as a risk factor for tuberculosis in South Korea.
METHODS
We performed a retrospective cohort study in a secondary referral hospital. The incidence of tuberculosis in a diabetic cohort was compared with that in a non-diabetic hypertensive cohort for 6 years. Diabetics who visited our diabetic clinic and non-diabetic hypertensive patients who visited our cardiology clinic from Jan 2004 to April 2004 were assigned to the diabetic cohort and the non-diabetic hypertensive cohort, respectively. Patients in each cohort had to receive medications to control their diseases. Patients with end-stage renal disease, malignancy, or HIV infection were excluded. Relative risk and tuberculosis-free survival rates of each cohort were calculated.
RESULTS
The incidences of tuberculosis were 32 in the diabetic cohort (n=2491; mean age, 59.1+/-11.8 years; 44.5% male) and ten in the non-diabetic hypertensive cohort (n=1885; mean age, 59.9+/-12.8 years; 41.6% male). The estimated annual incidences per 100,000 persons were 282.8 and 112.9, respectively. The relative risk was 2.220 (p=0.028; 95% confidence interval, 1.090~4.523). However, no significant difference in cumulative tuberculosis-free survival rate was observed between the cohorts (p=0.075).
CONCLUSIONS
A trend for a higher incidence of tuberculosis existed in diabetics, as compared to non-diabetic hypertensive patients, among a Korean population.